The present invention relates to a secure housing for an electronic unit, in particular a franking machine. The secure housing has at least a first housing part and a second housing part, which is connected releasably to the first housing part via at least one connecting device.
Numerous electronic units or devices require their internals to be protected against unauthorized access in order, on the one hand, to protect the user against possible risk or else also to prevent fraudulent manipulation of the unit. This prevention of undetected fraudulent manipulation is particularly important precisely in franking machines which, ultimately, produce an imprint corresponding to a monetary value, namely the franking of a letter or the like.
In order to protect the mail carrier against relatively large losses which may result from fraudulent manipulation, for example of the postal registers of the franking machine, which contain the accounting information for the franking imprints produced by the franking machine, franking machines or the associated accounting module usually have/has a secure housing of the generic type. The secure housing prevents the unauthorized access to regions of the franking machine which need to be secured. It goes without saying here that, although a defrauder can gain access to these regions which need to be secured, there are nevertheless indications on the housing, or parts connected thereto, which indicate that an attempt has been made to gain access, with the result that there is evidence of an attempted deception at least after the fact.
In order to render the unauthorized opening, or even an attempt at unauthorized opening, of the secure housing detectable, it is known to use, for example, conventional wire seals by means of which at least one screw connecting the two housing parts is leaded in a known manner. The solution, however, has the disadvantage that the wire seals involve relatively high outlay and/or are unwieldy and, in some cases, may also be damaged accidentally, for example during changeover of the set-up location of the unit.
It has also become known, for example in the case of devices for recording heating costs, to use pin-like connecting elements for connecting the housing parts. The connecting elements have to be destroyed in order to release the connection between the two housing parts. These variants, in turn, have the disadvantage that, on account of the configuration of the connecting pins, they are usually only suitable for relatively small housings.
It is accordingly an object of the invention to provide a secure housing for an electronic device, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which, while being straightforward to produce, ensures that intentional manipulation is reliably detected.
With the foregoing and other objects in view there is provided, in accordance with the invention, a secure housing for an electronic unit, comprising:
a first housing part and a second housing part;
at least one connecting device for releasably connecting the first housing part with the second housing part;
at least one covering device configured to prevent the housing from being opened without being noticed, the covering device being disposed to block an access to the connecting device and being removable from the first or second housing part only with noticeable damage being caused.
The present invention is based on the technical teaching that a housing which is straightforward to produce and makes it possible for intentional manipulation to be reliably detected is obtained if, in order to prevent unknown opening of the housing, there is provided at least one covering device which is arranged on and/or in the first or second housing part, blocks the access to the connecting device and can only be removed from the first or second housing part with noticeable damage, for example at least partial destruction, being caused.
On the one hand, the covering device advantageously ensures that intentional manipulation of the housing is readily detectable. On the other hand, the covering device makes it possible for the connecting device to be configured in a conventional manner, with the result that no significant outlay has to be provided for this purpose, which, in turn, has an advantageous effect on the production outlay, in particular the production costs.
The covering device also has the advantage that it may be of relatively small and straightforward design, since all that it has to do is to block the access to the connecting device. This facilitates to a considerable extent the production both of the covering device and of the first and second housing parts.
The connecting device may be designed in a conventional manner, for example in the form of one or more screws, hooks, etc. via which the two housing parts are connected in a conventional manner. In the case of the screw, the covering device then needs merely, for example, cover the screw head, which is otherwise accessible for release purposes, and, accordingly, may be of very small, straightforward and compact configuration.
In the case of preferred variants of the housing according to the invention, it is provided that the connecting device comprises fastening means via which it is fastened releasably on the first housing part. It is thus advantageously possible to provide connecting devices in the case of which the connection between the first and second housing parts is possible, during the production of the unit, via a connecting mechanism which is more straightforward to join than that of the connection between the connecting device and the first housing part.
In the case of preferred variants of the housing according to the invention, it is provided that the connecting device is designed in the manner of a snap-in connection. In this case, a constituent part of the snap-in connection is then fastened on the first housing part via the fastening means. This connection may take place long before the rest of the unit is installed, with the result that, in order to complete the unit, following installation of the internals of the unit, all that is still required is for the second housing part to be placed in position and attached via the snap-in connection.
It goes without saying, however, that the constituent parts of the snap-in connection may each be fixedly connected to the associated housing part and the covering device then merely blocks the access by way of the first or second housing part to at least one of these constituent parts, via which, if appropriate using corresponding tools, the connection between the two housing parts can be released.
The covering device may be connected to the first housing part in any desired manner such that, upon removal from the first housing part or attempted removal therefrom, it is noticeably damaged, i.e. at least partially destroyed or impaired such that this is readily detectable at least to an experienced observer. For this purpose, the covering device may be integrally connected, e.g. welded, to the first housing part or connected thereto with a force fit, e.g. adhesively bonded thereto.
In the case of variants of the invention which are preferred because the noticeable destruction or damage is most easily ensured, the covering device is connected with a form fit to the first housing part. The covering device is further preferably connected to the first housing part via a snap-in connection which can only be released with at least partial destruction being caused. This variant has the advantage that, in addition, the connection to the first housing part can be produced particularly straightforwardly.
It is understood, in addition, that the above-mentioned types of connection between the covering device and the first housing part may also, of course, be combined with one another in any desired manner.
In the case of favorable developments of the housing according to the invention, the connecting device comprises at least one first connecting element, which is connected releasably to the first housing part, and at least one second connecting element, which interacts with the first connecting element and is arranged on the second housing part. This makes it possible to realize in a particularly straightforward manner the abovementioned connections between the first and second housing parts, the connections utilizing, during the production of the unit, a connecting mechanism which is more straightforward to join than that between the first connecting element and the first housing part. In this way, the connecting device may be designed, for example, simply in the manner of the abovementioned snap-in connection. It goes without saying here, of course, that it is also possible for the two connecting elements to be connected releasably to the respective housing part in an appropriate manner.
On account of being straightforward to realize, the first connecting element is preferably designed in the manner of a hook which engages in an undercut of the second connecting element in order to produce the connection between the first and second housing parts. In order to produce a connection designed in the manner of a snap-in connection, at least the first connecting element is further preferably designed in a resilient manner and, in addition or alternatively, is arranged in a correspondingly resilient manner, for example is fastened, for example, on a resilient section of the relevant housing part or is fastened there by a corresponding resilient element.
It goes without saying that the above-mentioned connections between the first and second housing parts, once the covering element has been fitted, are designed and arranged such that they can only be released again when the covering element is removed.
This may preferably be realized in that the connecting device is arranged straightforwardly within the housing.
It is also possible, however, for the connecting device to be arranged outside the housing, in which case the covering element is dimensioned and designed such that it covers at least all the regions of the connecting device via which the connection could be released. The covering element is preferably dimensioned and designed here such that it covers the entire connecting device and thus protects the latter against unauthorized access.
In the case of variants of the housing according to the invention which are preferred because they are particularly straightforward and reliable, the fastening means comprise a screw-connection. On account of the usually very robust construction, this additionally ensures that the connection between the two housing parts can be released a number of times, for example for authorized, routine maintenance or testing of the unit, without the functional capability of the connecting device being impaired as a result.
It may be sufficient to provide one of the above-mentioned connecting devices on or in the housing. In the case of particularly preferred variants of the housing according to the invention, however, two or more of the connecting devices described are provided. This makes it possible to realize housing parts which are particularly straightforward to assemble.
The present invention also relates to an electronic unit or device, in particular a franking machine, having a corresponding housing according to the invention, since in this case the above-described advantages can be achieved to particular effect.
With the above and other objects in view there is also provided, in accordance with the invention, a secure housing for an electronic unit, such as a franking machine, comprising:
a first housing part, a second housing part, and at least one connecting device for releasably connecting the first housing part with the second housing part;
a magnetic element carried by the first and/or second housing parts and a sensing element for sensing a change in a magnetic field generated by the magnetic element; and
a memory connected to the sensing element for receiving a signal from the sensing element.
This further variant of the invention, which may possibly be used in addition to the above-described variants, straightforwardly ensures that the housing cannot be opened without this being noticed. Here, a magnetic element is disposed on a housing part and a sensing element is provided for sensing a change in the magnetic field in the region of the unit. The sending element is connected to a memory of the unit and/or a processing device of the unit for receiving the signals from the sensing element.
This makes it possible to sense the removal of the housing part on which the magnetic element, for example, a straightforward permanent magnet, is arranged, since there is a change in the magnetic field in the region of the unit. This operation of sensing a change in the magnetic field corresponding to the removal of the housing part may then be registered by or in the processing device of the unit or by writing to the memory and, at a later point in time, for example during an inspection or the like, ascertained and, in addition, or alternatively, displayed of its own accord.
In addition or alternatively, of course, upon occurrence of the change in the magnetic field which corresponds to the removal of the housing part, and thus upon occurrence of a corresponding sensing signal from the sensing element, it may be provided that the unit is moved into a certain operating state, preferably into a blocking state, which the user cannot leave again without corresponding authorization.
The magnetic element and the sensing element are coordinated with one another so as to produce a change in the magnetic field which can be sensed by the sensing element. By virtue of a suitable selection of the magnetic element, the change in the magnetic field is preferably characteristic, such that the change can be reliably distinguished from other changes in the magnetic field in the region of the unit which may occur during normal operation of the unit.
The sensing element is preferably coordinated here such that it only emits a corresponding sensing signal to the memory and/or the processing device when the characteristic change actually takes place, with the result that it is only this change which has to be sensed and there is no need for any further evaluation or further processing in the processing device or following read-out of the registered data which correspond to the registered changes in the magnetic field.
The sensing element is preferably accommodated on the main board of the unit since it can thus easily be connected to the processing device and/or the memory. This sensing element is preferably a so-called reed switch.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a secure housing for an electronic unit, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.